The other night my truck sat out in the freezing rain for a while, and then I pulled it into the garage. When I shut it off, the heater **** was in the defrost position. I did not hear the fan running, and I was out in the garage for a while, so I would have heard it.

The next morning I came out to the garage, and heard the blower motor running. No key in the ignition. Of course, the battery was too weak to start the truck, and I had to jump it.

Throughout the rest of the day, I would check, and the heater would run with the key off. The next day, i would hear a relay clicking, but the blower wouldn't run. Now, it seems to be back to normal.

Any ideas what happened? There must be a relay that supplies power to the heater panel. A stuck relay doesn't make sense though, because it "turned itself on" overnight.

Thanks!

 

Sounds like a short to me. The relay may have gotten power from a cut wire or other short grounding itself to the chassie.

I would check the wires out and maybe see if thier isn't a short somewhere.

Now if the fan was the only thing running that normally runs only when the switched power is on (have the key in) then you should be able to pinpoint it better.

I unfortunatly don't have access to schmatics for the Fords but you may be able to find a book or if it's under warrenty bring it in.

Good luck to you, hope you find it.

The other possibility is ghost, or a talented rat messing with you

 

Good luck... very hard to say but I'd tend to lean towards the 'short' side...

Then again, I've seen gremlins do some wild stuff!

RP

 

Took it to the dealer, and since it wasn't happening at that time, they didn't want to look into it too deeply.

Apparantly asking for a little deductive reasoning and doing something like inspecting the wiring harness was a little too troublesome for them.

At least it's now documented in case it happens again.

 

Interesting: My '98 F150 truck did the same a month ago. Then some mornings it would not start. But the battery checked out OK. As did the fairly new starter. After many twists of the key, finally the truck would start.

Once the weather warmed up, the starting problem fixed itself. Wasted $150 on two mechanics (Ford and independent) who could not figure out the problem (checked the ignition, battery, starter, fuses, etc).

Can't say I'm very impressed with my first F150. The Ranger I had worked just fine for all the years I owned it. This truck is nothing but trouble.